Combination visualization in same ax

Question

dear colleagues! I had next problem with visualization my data. Firstly, i want add my city, which i want see like basemap.

import contextily

city = contextily.Place("Калининградская область")
ax = city.plot()

And all is right, but i want add my geodataframe with LineString geometry type.

After i see that my data with lines scale my basemap and all crash. Do have you ideas what is reason for?

city = contextily.Place("Калининградская область")
ax = city.plot()
gdf.to_crs("EPSG:3857").plot(column='avg_speed', cmap='hot',
                             marker='_',
                             ax=ax,
                             alpha=1,
                             markersize=5,
                             legend=True,

I try create general ax for both ploting image, but it wasn't working.